An experimental study of effect of printed thickness on the mechanical properties of LPBF produced AlSi10Mg

Abstract

Additive manufacturing process allows fabrication of parts with a broad range of sizes with high resolution. This size variation introduces new mechanical properties within the printed component, which creates a significant challenge for the qualification of additively manufactured parts. This unresolved issue hinders the implementation of additive manufacturing in high performance engineering applications. To attain optimal performance of additive components, it is imperative to gain a comprehensive understanding of the size effect. While many studies have explored the mechanical properties and microstructure of additively manufactured AlSi10Mg, the size effect remains relatively undefined. To gain more knowledge on this matter, AlSi10Mg samples with four different thicknesses were fabricated using a selective laser melting machine and tensile tests were performed to characterize the material behavior. Stress-strain curves were derived with consideration of nominal and measured cross section and the resulting diagram showed a considerable difference for the samples with minimum thickness, which was 0.5 mm. Comparing the results between the 2 mm and 0.5 mm thick specimens demonstrated more than 50 percent decrease in tensile properties including ultimate tensile strength and elongation at fracture. Also, the study of strain rate indicated no significant strain rate sensitivity for either thickness. These findings contribute to better understanding the size effects on behavior of printed AlSi10Mg, promoting further commercial adoption of this material.